From The National Geographic:
Flaring the gills that give the species its name, a frilled shark swims at Japan’s Awashima Marine Park on Sunday, January 21, 2007. Sightings of living frilled sharks are rare, because the fish generally remain thousands of feet beneath the water’s surface. Spotted by a fisher on January 21, this 5.3-foot (160-centimeter) shark was transferred to the marine park, where it was placed in a seawater pool. “We think it may have come to the surface because it was sick, or else it was weakened because it was in shallow waters,” a park official told the Reuters news service. But the truth may never be known, since the “living fossil” died hours after it was caught.
More here.